I have opened my 2013 Salvage Nissan Leaf battery, and removed some of the modules. I’ll post a complete guide with more pictures after I finish, but I wanted to post some photos of the differences between the 2011/2012 batteries and the 2013 battery.
From the outside of the battery the big difference is that there is a 2nd HV connector on the front that goes to the cabin heater, There are no 13mm bolts holding the lid on, and the number of 10mm bolts around the lid is significantly fewer than with previous years (2011/2012). Also, the torx/pin security screws holding the service disconnect bracket in place have been replaced by standard 10mm bolts.
The reason for having less bolts holding the lid on is that instead of a gasket, the lid is sealed down (very well!) with a thick bead of some type of waterproof glue/gasket material. To remove the lid, I had to chisel around three sides with a rubber mallet and a 1 1/2″ putty knife (I just bent the 4th side of the lid up to save time). Luckily, the lid fits down over a 1″ high lip of steel, so you can safely use an air chisel (if you are lucky enough to have one) to break the seal more quickly.
Inside the battery, the end plates have a different shape, and there is some type of plastic cover over the back row of 24 modules on edge. Also, the modules look different, so if you are buying a module, you can easily tell the difference. There is a “cut” or split” all the way around the edge of the module, and more air vents on the top and bottom. I suspect this results in the interior cells being just slightly cooler in operation. I don’t know if they changed the actual chemistry, or just added more convective cooling opportunities.